All headphones of the CX, CXL series are working with the same electrodynamic transducer technology. Variants of the CX, CXL series: CX 6 TRAVEL CX 150 CX 160 CX 175 CX 180 CX 200 STREET II CX 213 CX 215 CX 250 CX 270 West CX 275 CX 271 CX 280 CX 281 CX 300 CX 400-II PRECISION CX 301 CX 300-II PRECISION 2.